Combination rug and floor vacuum cleaner nozzle

ABSTRACT

A combination rug and floor vacuum cleaner nozzle has a suction inlet which serves as one cleaning tool and is movable over a porous object like a rug to remove dirt therefrom. A brush serving as another cleaning tool is mounted on the nozzle at the vicinity of the suction inlet for movement between upper and lower positions respectively above and below the suction inlet. The suction inlet functions to remove dirt from a rug when the brush is in its upper position and the brush functions to remove dirt from a smooth object like a floor when it is in its lower position. Pneumatic mechanism operable responsive solely to operating conditions prevailing when the nozzle is moved either over a smooth object or a porous object becomes effective to automatically shift the brush above or below the suction inlet, respectively, to position the proper cleaning tool in contact with the object to be cleaned even when the vacuum producing ability of the vacuum cleaner connected to the nozzle varies within wide limits.

United States Patent Schwartz Oct. 30, 1973 COMBINATION RUG AND FLOORVACUUM CLEANER NOZZLE [75] Inventor: Osten Schwartz, Varmdo; Sweden [73]Assignee: Aktiebolaget Electrolux, Stockholm,

Sweden [22] Filed: Sept. 3, 1971 [21] Appl. No.: 177,665

[ 1 Foreign Application Priority Data Sept. 9, 1970 I Sweden ..l2260/7015/373 [51] Int. Cl A47] 9/06 [58] Field of Search 15/319, 365, 368,15/371, 373, 419

[56] References Cited UNITED STATES PATENTS 2,638,763 9/l954 Pfaffle etal. l5/37l 3,497,903 3/1970 Jonsson l5/3l9 3,599,271 8/1971 Ljung et al15 319 3,659,3l2 5/1972 Mattsson...... l5/3l9 3,660,864 5/l972 Schwartz15/319 Primary Examiner-John Petrakes Assistant ExaminerC. K. MooreAttorney-Edmund A. Fernander [57] ABSTRACT A combination rug and floorvacuum cleaner nozzle has a suction inlet which serves as one cleaningtool and is movable over a porous object like a rug to remove dirttherefrom. A brush serving as another cleaning tool is mounted on thenozzle at the vicinity of the suction inlet for movement between upperand lower positions respectively above and below the suction inlet. Thesuction inlet functions to remove dirt from a rug when the brush is inits upper position and the brush functions to remove dirt from a smoothob ject like a floor when it is in its lower position. Pneumaticmechanism operable responsive solely to operating conditions prevailingwhen the nozzle is moved either over a smooth object or a porous objectbecomes effective to automatically shift the brush above or below thesuction inlet, respectively, to position the proper cleaning tool incontact with the object to be cleaned even when the vacuum producingability of the vacuum cleaner connected to the nozzle varies within widelimits.

26 Claims, 13 Drawing Figures COMBINATION RUG AND FLOOR VACUUM CLEANERNOZZLE BACKGROUND OF THE INVENTION 1. Field of the Invention One factorwhich influences dust absorption is the speed of the air flow throughthe nozzle for bodily moving and transporting dust and dirt particlesfrom the ob ject to be cleaned to the dust bag in the suction cleaner.In a moving air stream, movement is imparted to a particle of dust ordirt by a force which is dependent upon positive atmospheric pressure atone side of the particle and a pressure at the opposite side thereofwhich is below atmospheric pressure. Hence, movement is impartedpneumatically to dust and dirt particles by a force which is dependentupon the difference between atmospheric pressure and the vacuumdeveloped by the cleaner. The speed of the air flow increases withincrease in the volume of air moved per unit interval of time. Thecapacity of brushes and nozzles working on objects is a primary andbasic consideration which determines the ability of a suction cleaner toabsorb dust and dirt.

When brushes are employed to suck and draw dust particles fromessentially smooth objects like floors, for example, the penumatic forcejust referred to is not as great as it is when a porous object is beingcleaned. In cleaning porous objects like carpets, for example, a brushgenerally is not employed and instead a nozzle is employed having anoperating surface which is at the immediate vicinity of the suctioninlet opening and disposed about the latter. With a nozzle of this type,dust and dirt must be sucked or drawn from the pores of an object and ahigher vacuum is developed in the nozzle passageway so that movementwill be imparted pneumatically to dust and dirt particles by thepneumatic force referred to above which is dependent upon the differencebetween atmospheric pressure and the partial vacuum developed in thenozzle passageway which, under these conditions, is higher than thepartial vacuum developed when a brush is employed to clean objects whichare essentially smooth and less porous.

A combination rug and floor vacuum cleaner nozzle has an openingdefining a suction inlet and a brush mounted for movement on the nozzlebetween upper and lower positions, the brush in its upper position beingabove the suction inlet and in its lower position below the suctioninlet. When the brush is in its upper position the suction inlet isrendered operable to remove dust and dirt from porous objectslikecarpets and rugs. When the brush is in its lower position the brush isrendered operable to remove dust and dirt from smooth objects likefloors.

2. Description of the Prior Art In known multi-purpose nozzles of thekind heretofore provided the brush is moved pneumatically between itsupper and lower positions by mechanism which includes a rubber diaphragmto which the brush is connected, such diaphragm forming a wall of aspace in communication with the path of air flow of the nozzle which isat a partial vacuum. Due to the subatmospheric pressure in the nozzle,which varies in accordance with the physical characteristics of theobject over which the nozzle is moved, the diaphragm will flex to itsupper or lower position and move the brush to its upper or lowerposition on the nozzle.

In such known multi-purpose nozzles the diaphragm is biased to its lowerposition by a spring which is so adjusted that shifting of the brush onthe nozzle is promoted due to changes in the physical characteristics ofthe object over which the nozzle is moved. With a nozzle of this type,the vacuum producing ability of the vacuum cleaner connected to thenozzle should not vary within too wide limits. If the suction ability ofthe vacuum cleaner should decrease to an abnormally high extent, as whenthe dust bag of th vacuum cleaner becomes clogged with dust and dirt,the partial vacuum or suction pressure produced in the air flow path ofthe nozzle can become too small to effect movement of the brush betweenits upper and lower positions in the nozzle. Under these conditions thebrush may not be moved from its lower to its upper position and willremain in an operative position when a porous object like a carpet, forexample, is being vacuumed, which is objectionable. if the vacuumproducing ability of the vacuum cleaner should become excessive, thepartial vacuum produced in the air flow path of the nozzle can becometoo great and may effect movement of the brush from its lower to itsupper position when a smooth object like a floor, for example, is beingvacuumed, which also is objectionable.

SUMMARY OF THE INVENTION My invention relates to a combination rug andfloor vacuum cleaner nozzle of the kind referred to above in which abrush is mounted on the nozzle at the vicinity of the suction inlet formovement between upper and lower positions, the brush in its lowerposition being below the suction inlet and operable to remove dirt froma smooth object like a floor. The suction inlet becomes operable toremove dirt from a porous object when the brush is in its upper positionabove the suction inlet.

The brush is moved between its upper and lower positions by pneumaticmechanism having a control space connected by a passageway to a regionof the nozzle which normally is at a partial vacuum, such region beingin the path of flow of air from the suction inlet to the air outlet ofthe nozzle. A control valve is provided in the last-mentionedpassageway.

When the valve is open and air in the control space is at a firstpressure which is a partial vacuum, the pneumatic mechanism functions tomove the brush to its upper position against the biasing action ofresilient means. When the valve is closed and the air in the controlspace is at a second pressure, which is ambient air at atmosphericpressure, the mechanism functions to move the brush to its lowerposition with the biasing action of the resilient means.

It is an object of my invention to provide an improvement in acombination vacuum cleaner nozzle of this kind for controlling thevalve. I accomplish this by providing control means operable to controlthe valve responsive solely to the pressure differential of air in firstand second regions in its path of flow, such pressure differentialvarying with the physical characteristics of the surface being cleanedby the nozzle. With this construction, the pneumatic mechanism functionscorrectly to move the brush to its upper and lower positions withrespect to the suction nozzle even when the vacuum producing ability ofthe vacuum cleaner connected to the nozzle varies within wide limits andwhen the vacuum producing ability of the vacuum cleaner should becomeexcessive.

BRIEF DESCRIPTION OF THE DRAWING In the drawing,

FIG. 1 is a vertical sectional view of one half of a combination rug andfloor vacuum cleaner nozzle embodying my invention with the brushillustrated in its lower position and operative to perform cleaning;

FIG. 2 is a sectional view taken at line 2-2 of FIG.

FIG. 3 is an enlarged fragmentary sectional view of parts shown in FIG.2;

FIG. 4 is a view similar to FIG. 3 illustrating a modification of theinvention;

FIG. 5 is a fragmentary sectional view taken at line 5-5 of FIG. 1;

FIG. 6 is a fragmentary top perspective view of interior parts of thenozzle shown in FIGS. 1 and 2;

FIG. 7 is a sectional view, taken at lines 7-7 of FIGS. 1 and 6, withthe brush in its lower position and operative to perform cleaning;

FIG. 8 is a sectional view similar to FIG. 2 with the brush in its upperposition and inoperative to perform cleaning;

FIG. 9 is a view similar to FIG. 3 illustrating another modification ofthe invention;

FIGS. 10 and 11 are fragmentary views schematically illustrating theclosed and open positions of the valve shown in FIGS. 2 and 8;

FIG. 12 illustrates curves showing the difference in sub-atmosphericpressure at different regions of the nozzle passageway; and

FIG. 13 illustrates a curve showing the ratio of the sub-atmosphericpressures at different regions of the nozzle passageway as a function ofthe quantity of air moved through the passageway when the nozzle isbeing employed to clean a carpet and a smooth floor.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing, thecombination rug and floor vacuum cleaner nozzle 40 embodying myinvention comprises an elongated hollow body 41 including top and bottomparts 10 and 11, respectively, having a flexible diaphragm 18therebetween to provide top and bottom spaces 35 and 42, respectively.The top and bottom parts 10 and 11 are detachably connected together inany suitable manner (not shown).

The peripheral edge portion of the diaphragm 18 is clamped between theabutting outer edges of the body parts 10 and 11 and formed with anenlarged head 32 which serves as a bumper to protect objects againstwhich the nozzle 40 may strike when being moved back and forth over anobject or surface being cleaned. The diaphragm 18 desirably is formed ofa suitable elastomeric material like rubber, for example.

The hollow body 41 is provided with an upwardly inclined tubular member12. The tubular member 12 serves as an air outlet socket adapted to beconnected to a source of supply of air at a partial vacuum, such as avacuum cleaner, for example. The outlet socket 12 forms part of apassageway 16 which extends downwardly midway between the ends of thenozzle body 41 and terminates in an air inlet opening or suction inletdefined by spaced apart walls 13 which extend lengthwise of the body 41.It will now be understood that the suction inlet 15 has two branches atthe bottom of the nozzle 40 which extend outwardly from a central partof the body 41, the ceilings 13a of the branches sloping downward withthe higher inner ends thereof in communication with the lower end of thepassageway An apertured bottom plate 14 overlies the bottom part 11 atthe lower ends of the walls 13 to provide a smooth gliding surface whena porous object like a carpet or rug is being cleaned. Air sucked intothe suction inlet 15 throughout its length moves toward the center partof the nozzle 40 and then flows upwardly through the passageway 16toward the air outlet socket 12.

A four-sided brush 20 of annular form is disposed at the vicinity of thesuction inlet 15. The brush 20, which comprises parallel sides 20a andconnecting ends 20b, includes bristles 20c fixed to a brush back 20d ofannular form. The sides 20a of brush 20 are held at 190 at the undersideof a brush holder 19.

The diaphragm 18 is formed with a cup-shaped portion which receives anopen cup-shaped member 22. The member 22, which snugly rests in thecup-shaped portion of the diaphragm 18, is provided with a flange or rim22a at its open end. The cup-shaped portion of the diaphragm 18 isclamped at 43 between the rim 22a of the member 22 and the brush holder19.

It will now be understood that the brush holder 19, cup-shaped portionof the diaphragm 18 and cupshaped member 22 form a unitary component ofthe nozzle and are vertically movable as a unit when movement isimparted to the diaphragm 18. The diaphragm 18 is provided with acorrugated section 18a of annular form which is closely adjacent to theflange 22a to promote flexing movement of the diaphragm. Further, itwill be understood that the structure just described and illustrated inFIG. 6, which is embodied in the side of the nozzle 40 shown in FIG. 1,is duplicated for the side of the nozzle at the other side of the outletsocket 12.

The bottom body part 11 is apertured at to receive the brush bristles20c which move between upper and lower positions with respect to thesuction inlet 15. When the brush 20 is in its upper position shown inFIG. 8 the apertured plate 14 fixed to the bottom body part 11 functionsto effect cleaning of porous objects like a rug or carpet, as explainedabove. When the brush 20 is in its lower position below the suctioninlet 15, the brush is adapted to effect cleaning of smooth objects likea floor 43, as shown in FIG. 2. A coil spring 23 is provided in the topspace 35 with its upper end bearing against the top part 10 of thenozzle body 41 and its lower end bearing against the bottom of thecupshaped member 22. Hence, the spring 23 functions to urge the brush 20to its lower position shown in FIG. 7.

When the nozzle 40 is being moved over a smooth surface like the floor43, for example, the air in space 35 above the diaphragm 18 will be atatmospheric pressure, as will be explained presently, and the spring 23at each side of the outlet socket 12 is rendered operable to move thediaphragm 18 and brush 20 downward, as shown in FIGS. 2 and 7. When thenozzle 40 is being moved over a porous surface 44 like a rug, forexample, the air in the space 35 will be at sub-atmospheric pressure ora partial vacuum, as will be explained presently, whereby the diaphragm18 will flex upwardly against the biasing action of each of the springs23 to raise the brush 20 to its upper position shown in FIG. 8.

The space 35 is connected to a first region 16a in the passageway 16, inwhich air at a partial vacuum is flowing from the suction inlet to theair outlet 12, by structure defining a passageway 45 having first andsecond portions 45a and 45b, respectively. The first portion 450includes an elongated opening or passage 46 in the wall of the topnozzle part 10 which extends from the region 16a of the passageway 16 toa chamber 47 having a larger cross-sectional area than the passage 46.The first portion 45a terminates in an opening of the chamber 47 whichhas a sharp edge 48, as shown in FIGS. 2 and 3.

Th passageway 45 has a break at the open end of the chamber 47, thesecond portion 45b thereof at such break including a chamber 49 ofannular form which is disposed about the chamber 47, as seen in FIGS. 2and 3. Referring now to FIGS. 1 and 5, it will be seen that the chamber47 is elongated and is disposed at the center of the nozzle 41. Thechamber 49, which is disposed about the chamber 47, also is of elongatedform and provided with end openings 50.

As will be explained presently, a valve 51 is provided at the break inthe passageway 45 which functions to close and open the break betweenthe two portions 45a and 45b thereof. Assuming that the valve 51 is inits open position during operation of the nozzle, as shown in FIG. 8,air can flow toward the region 16a of the passageway 16 in a path offlow which includes passage 46, chamber 47, chamber 49 and end openings50 therein to the spaces 35 in each arm of the nozzle body 41, one ofwhich is illustrated in FIG. 1. When this operating condition prevailsthe diaphragm 18 will flex upward against the biasing action of thespring 23 to raise the brush to its upper position in the mannerexplained above and shown in FIG. 8.

If we now assume that the valve 51 is closed during operation of thenozzle, as shown in FIG. 2, air at a partial vacuum cannot flow towardthe region 16a of the passageway 16 from the space 35. Under thisoperating condition the air in the space will be at atmosphericpressure, and the spring 20 is rendered operable to move the diaphragm18 and brush downward, as shown in FIG. 2. Ambient air at atmosphericpressure can flow into the space 35 through an opening 52 in the nozzlebody 41. The opening 52 may be referred to as a leakage opening forambient air to flow into the space 35. Ambient air also can flow intothe space 35 through cracks in the joints between the nozzle parts whichmay avoid the need to provide the opening 52.

As shown in FIGS. 2 and 3, the valve 51 comprises a relatively thindiaphragm having its peripheral edge portion clamped between wallstructure defining the chamber 49 above the diaphragm and a chamber 53below the diaphragm. The neutral or non-stressedposition of thediaphragm 51 is shown in FIGS. 2, 3 and 4. During operation of thenozzle the diaphragm 51 in its closed position, due to its flexibility,will assume a position more like that schematically shown in FIG. 10.

In accordance with my invention I provide control means responsivesolely to the pressure differential of air in first and second regionsin the path of air flow 16, such pressure differential varying with thephysical characteristics of the surface being cleaned'by the nozzle andover which the nozzle body is moved. I accomplish this by making use ofthe portion 454 of the passageway to connect the chamber 47 above and atone side of the diaphragm valve 51 to the region 16a of the passageway16; and by connecting the chamber 53 below and at the opposite side ofthe diaphragm valve 51 through an opening 54 in the nozzle wallstructure to a region 16b of the passageway 16 which is removedlengthwise of the passageway from the region 16a.

During operation of the nozzle the partial vacuum at the region 1612will be different from that at the region 16a due to the pressure dropof air flowing lengthwise of the passageway 16 between these regions. Byproviding a construction 55 in the passageway 16 between the regions 16aand 16b, the pressure differential between these regions can beincreased. The chamber 47 will acquire the partial vacuum or negativepressure prevailing in the passageway 16 at the region 16a which is atthe right of the constriction 55. The chamber 53 will acquire thepartial vacuum or negative pressure prevailing in the passageway 16 atthe region 16b which is at the left of the constriction 55, the negativepressure at the region 16b having a lower absolute value than thenegative pressure at the region 16a.

As shown in FIGS. 2 and 3, the sharp edge 48 at the open end of thechamber 47 defines a seat for the diaphragm 51 when the latter is in itsclosed position. The ratio between the cross-sectional area defined bythe sharp edge or seat 48 and the total area of the diaphragm valve 51is such that the conditions of movement of the diaphragm valve at bothsides of the edge of the seat 48 will be the same. In other words, thezones of the diaphragm valve 51 at both sides of the edge of the seat 48and immediately adjacent thereto will flex and move in substantially thesame manner as schematically illustrated in FIG. 10. This means that thediaphragm valve 51, which is very resilient, can bulge to the sameextent and degree at both sides of the edge of the seat 48.

In the nozzle shown in FIGS. 1 to 3 and 5 to 8 and described above, theoperating features inherent in its operation can be expressed asfollows:

I. The force for operating the shifting diaphragm 18 of nozzle 40 havingthe valve 51 is greater than in nozzles which do not have such a valve.

2. Shifting of the working member, that is, the brush 20 occurs onlywhen the throttling resistance between the nozzle 40 and the surface tobe cleaned changes and independently of changes in the suction abilityof the vacuum cleaner. The suction ability of the vacuum cleaner canvary with clogging of a dust bag and variations in voltage of theelectrical supply to the vacuum cleaner motor, for example.

Referring to FIGS. 10 and 11, which schematically illustrate the closedand open positions of the diaphragm valve 51 in FIGS. 2 and 8,respectively, the pressure designations refer to the sub-atmospheric ornegative pressures and are represented as forces of tension. With thisdefinition the pressure of ambient air outside the nozzle is representedby the equation 17 5 In FIGS. 10 and 11 g and q designate the relativepermeability in the openings with the areas a, and a With localthrottling zones:

so that q, +q =1.

When the diaphragm valve 51 is open and space 35 is connected to theambient and, via the valve, exposed to the pressure p the resultingpressure will be:

In the following:

F the sealing force in the valve F the force acting on the diaphragmwhen the valve is open a and b are dimensions of diaphragm 53 as shownin FIG. 10.

The equations of equilibrium will be:

on a floor on a carpet be within the respective range of work. Theconditions therefor are a/(a b) lp max. and

qz lam/p2".

Conditions of stability When F equals zero when passing over from floorto carpet and hence:

a/(a b) p /p o,

1",, has to assume a positive value Should F,, become negative, thediaphragm will return to sealing position and will then open again, thisaction of the diaphragm being repeated. The diaphragm will thusoscillate.

Accordingly, the condition of stability will be a/(a b) q The samecondition is applicable when changing over from carpet to floor.

Shifting of the brush is independent of the suction ability of thevacuum cleaner The pressure fall through the nozzle to the two openingsof channels 54 and 46 can be expressed as a quadratic function of thequantity of air (Q m /min.):

PI I'Q Pz 2'Q wherein K and K are coefficients only depending on theflow conditions into the nozzle to the positions where p, and p, are tobe determined. With the nozzle in unchanged position on the same workingsurface K and K will be constant and will also be constant, independentof Q. Shifting as set for a certain value of p lp p /p between the limitvalues (p /p max. and (p /p min. by appropriate dimensioning of a/(a b)and q will then always occur in the same point relative to the limitvalues mentioned.

The force operating the brush shifting mechanism Sub-atmospheric ornegative pressure (1 p; acting on the shifting diaphragm 18 is used forshifting of the brush 20. From FIG. 13 it appears that at anappropriately set shifting point q (approximately equals) 0.6 and p 440mm wc (water column) giving a q p 240 mm we. The shifting point will besituated so that a good margin to the limit values for floor and carpet,respectively, is obtained. Moreover, a/(a b) q which will give stabilityin the shifting operation. Should only the difference in p between floorand carpet be used for shifting at the same vacuum curve (shown in FIG.12) the sub-atmospheric or negative pressure acting on the brushshifting diaphragm 18 should only be mm wc even if shifting occurred atthe limit values.

The function of the diaphragm valve 51 is determined by the negativepressures prevailing on opposite sides of the diaphragm at the zoneclosest to the edge of the seat defined by the sharp edge 48. The ratioof the area defined by the seat 48 to the total area of the diaphragm isof secondary importance. As pointed out above, the only requirement thatmust be satisfied is that the distance between the edge of the seat 48and the region of the diaphragm 51 at its peripheral edge portion, atwhich it is fixed, is sufficient to enable the resilient diaphragm tomove to the same extent and degree at the zone at both sides and closeto the edge of the seat 48 as schematically illustrated in FIG. 10.

When the nozzle 40 is employed to clean a smooth surface like the floor43 as shown in FIGS. 2 and 7, the absolute value of the negativepressure in the passageway 16, and also in the chamber 53, will becomparatively low while the quantity of air being moved through thepassageway will be relatively high. By providing the constriction 55 theabsolute value of the negative pressure at the open end of the passage46 adjacent to region 16a of the passageway 16, which is to the right ofthe constriction 55, and also the absolute value of the negativepressure in the chamber 47, will be considerably higher than theabsolute value of the negative pressure in the passageway 16 to the leftof the constriction 55 due to the relatively high pressure drop acrossthe latter. Since air can leak through the opening 52 into the space 35and also into the space 49 through its end openings 50, the chamber 49will approximately be at atmospheric pressure. The passageway 16 at theconstriction 55 is so dimensioned that, under the operating conditionsthat have been assumed, the diaphragm valve 51 will be in its closedposition against the seat 48. Consequently, the diaphragm 18 will bebiased downward by the spring 23 and move the brush 20 to its lowerposition below the suction inlet 15, as shown in FIGS. 2 and 7.

When the nozzle 40 is employed to clean a porous object like a rug, theabsolute value of the negative pressure in the passageway 16 will becomparatively high while the quantity of air being moved through thepassageway will be small. The difference between the negative pressureson opposite sides of the constriction 55 will be small due to therelatively low pressure drop across the latter and hence the negativepressures prevailing in the chambers 47 and 53 will be approximatelyequal. Under these operating conditions the diaphragm valve 51 will moveto its open position.

Under these last-mentioned operating conditions the space 35, and alsothe chamber 49, will assume a negative pressure which will be sufficientto overcome the downward biasing action of the spring 23. When thisoccurs the brush 20 will be retracted into the space 42 above theapertured plate 14.

It will now be understood that the valve 51 is movable between open andclosed positions and in a second passageway 45 intermediate the endsthereof and acted upon by the pressure differential of air at a partialvacuum in a first region 16a of a first passageway 16 and of air at apartial vacuum in a second region 16b of the first passageway 16. Thevalve 51 moves to its closed position, as seen in FIGS. 2, 3 and 10,when the pressure differential is above a definite value and the rate atwhich air flows through the first passageway 16 is in a first range.This is the condition that prevails when cleaning the floor 43, as shownin FIG. 2. The valve 51 moves to its open position, as seen in FIGS. 8and 11, when the pressure differential is below the definite value andthe rate at which air flows through the first passageway 16 is in asecond lower range. This is the condition that prevails when cleaningthe rug 44, as shown in FIG. 8. Further, the movable mounting means forthe brush 20, which includes the diaphragm 18 and can be referred to asthe second operating surface, is rendered operable to move the brush 20to its upper position when the valve 51 is in its open position.

More particularly, the spring means 23 acts on the diaphragm to move thesecond operating surface or brush 20 in a first direction to its lowerposition, the nozzle body 41 having a space 35 defined by wall meansformed by the top body part and the diaphragm 18. The section 45b of thesecond passageway 45, which is connected to the mounting means ordiaphragm 18 in the manner explained above, is in communication with thespace 35, as shown in FIGS. 1, 2 and 5.

The mounting means for diaphragm 18 is acted upon by air at a partialvacuum when the valve 51 moves to its open position and the secondpassageway 45 is open. Such air at a partial vacuum and in the space 35is operable to overcome the spring means 23 and move the secondoperating surface or brush 20 in a second opposite direction to itsupper position. As explained above, the wall means formed by the topbody part 10 and, with the diaphragm l8, defining the space 35, has anopening 52, as seen in FIG. 1, for ambient air at atmospheric pressureto flow into the space 35.

The nozzle 40 is supported by rollers or wheels 56 which function tohold the nozzle at one level with respect to a smooth surface in themanner shown in FIG. 2. The rollers 56 are of such thickness that theywill sink into a carpet or rug and maintain the apertured plate 14 atthe suction inlet in operative position to perform cleaning, as shown inFIG. 8.

In FIG. 4 I have shown a modification in which an additional throttlingzone 57 is introduced between the passage 46 and the chamber 47, wherebythe negative pressure in the chamber 49 will attain an optimal value.However, throttling in the passage 46 must not be excessive because, insuch case, the nozzle 40 will be slow-acting and there will be risk,when the nozzle is moved from a floor to a carpet, for example, that thebrush will not immediately leave its working position. Since aircontinuously leaks into the space 35 and the chamber 49 through theaperture 52, the diaphragm valve 51 will open at regular intervals andmove to its closed position when the nozzle 40 is employed on a porousobject like a carpet. However, by suitably dimensioning the spring 23and the throttling means disposed on one hand in the passage 46 and onthe other hand at the aperture 52, the negative pressure in the chamber49 will not fall to such an extent when the diaphragm valve 51 is closedthat the diaphragm 118 will be acted upon in a downward direction beforethe diaphragm valve 51 opens again. Therefore, the brush 20 will beretracted continuously in the nozzle body 41 during vacuum cleaning of acarpet or rug.

FIG. 9 illustrates another modification in which a piston-like part 58is connected to the diaphragm valve 511 in such manner that thepiston-like part moves rectilinearly to and from the seat 48. In FIG. 9the elongated passage 46 in the wall of the top nozzle part extendsdownward to a chamber 47 having a larger cross-sectional area than thepassage 46. Further, the chamber 53 in the first-described embodiment ofFIGS. 2 and 3 is eliminated in the modification of FIG. 9 in which thediaphragm valve 51' defines a wall part of the nozzle passageway 16 atthe region 16b thereof.

When the valve 51' in FIG. 9 is open an operating condition isestablished which is similar to that illustrated in FIG. 8 for the firstdescribed embodiment. In such case air at a partial vacuum can flow fromthe region 16a of the passageway 16 through passage 46 and chamber 47directly into the spaces 35 in each arm of the nozzle body, one of whichis shown in FIG. 9 with its leakage opening 52' which corresponds to theleakage opening 52 seen in FIG. I.

In the modification of FIG. 9 the ratio between the area defined by theseat 48 and the total diaphragm area is of great importance while thenegative pressure at zones closely adjacent to the edge of the seat 48'is not important. Then the cross-sectional area of the portion of thediaphragm valve 51' facing the region 1612 of the nozzle passagewayshould be approximately twice the cross-sectional area defined by theseat 48'.

I claim:

l. A vacuum cleaner nozzle which includes a. first and second operatingsurfaces for performing different types of cleaning,

b. said nozzle comprising a body including means defining a firstpassageway having a suction inlet at the vicinity of said operatingsurfaces and an outlet adapted to be connected to a source of supply ofair at a partial vacuum, said first passageway providing a path of flowfor air between the inlet and outlet,

c. means for mounting said second operating surface on said body formovement between upper and lower positions with respect to said firstoperating surface, said first operating surface functioning to clean anobject with which it is in contact when said second operating surface isin its upper position and said second operating surface functioning toclean an object with which it is in contact when it is in its lowerposition,

(I. means providing a second passageway having one end thereof incommunication with a first region of said first passageway and theopposite end thereof in communication with said movable mounting means,

e. a valve which is movable between open and closed positions and insaid second passageway intermediate the ends thereof and acted upon bythe pressure differential of air at a partial vacuum in said firstregion of said first passageway and of air at a partial vacuum in asecond region of said first passageway,

f. said valve moving to its closed position when said pressuredifferential is above a definite value and the rate at which air flowsthrough said first passageway is in a first range and moving to its openposition when saidvpressure differential is below the definite value andthe rate at which air flows through said first passageway is in a secondlower range, and

. said movable mounting means being rendered operable to move saidsecond operating surface to its upper position when said valve is in itsopen position.

2. A vacuum cleaner nozzle as set forth in claim 1 in which said secondregion in said first passageway is removed lengthwise therein from saidfirst region, and means between said first and second regions forthrottling air flowing in said first passageway between said regions.

3. A vacuum cleaner nozzle as set forth in claim 2 in which said secondpassageway has a break at which the adjacent ends of two sectionsthereof terminate, one of said sections in communication with said firstregion of said first passageway terminating in an opening at said breakwhich defines a seat against which one face of said valve is adapted tomove in sealing relation therewith, a first segment of said one face ofsaid valve moving against said seat defining a first part of the area ofsaid valve, and the other of said sections of said second passageway incommunication with said movable mounting means also terminating at anopening at said break, a second segment of said one face of said valveco-acting with the last-mentioned opening of the other of aid sectionsdefining a second remaining part of said valve area, and the oppositeface of said valve being in communication with said second region ofsaid first passageway.

4. A vacuum cleaner nozzle as set forth in claim 3 in which said valvecomprises a flexible diaphragm, and means for securing the peripheraledge portion of said diaphragm in said body adjacent to said break insaid second passageway, the ratio of the area of the first part of saiddiaphragm to the entire cross-sectional area thereof being such thatflexing of said first and second segments of said diaphragm at opposingsides of said seat in substantially the same manner is promoted whensaid diaphragm moves to its closed position.

5. A vacuum cleaner nozzle as set forth in claim 3 in which said valvecomprises a resilient diaphragm, means for securing the peripheral edgeportion of said diaphragm in said body adjacent to said break in saidsecond passageway, said seat being defined by a sharp edge formed atsaid break by the opening in said first section of said secondpassageway, and said diaphragm having a larger cross-sectional area thanthe crosssectional area of said seat with the radial distance of saiddiaphragm from said seat to the peripheral edge portion thereof beingsuch that zones of said diaphragm at both sides of the edge of said seatand immediately adjacent thereto flex and move in substantially the samemanner.

6. A vacuum cleaner nozzle as set forth in claim 1 in which said meansfor movably mounting said second operating surface on said bodycomprises a diaphragm, spring means acting on said diaphragm for movingsaid second operating surface in a first direction to its lowerposition, and said movable mounting means being acted upon by air at apartial vacuum when said valve moves to its open position and saidsecond passageway is open, such air at a partial vacuum being operableto overcome said spring means and mov said second operating surface in asecond opposite direction to its upper position.

7. A vacuum cleaner nozzle as set forth in claim 3 in which said firstsection of said second passageway includes two portions, a first portionof which is nearer to said first region of said first passageway and asecond portion of which is nearer to said valve and has the openingdefining said seat, and the cross-sectional area of said second portionat said seat being greater than the cross-sectional area of said firstportion.

8. A vacuum cleaner nozzle as set forth in claim 7 in which the junctionbetween the first and second portions has a restriction which throttlesair flowing therethrough when said valve is in its open position.

9. A vacuum cleaner nozzle as set forth in claim 3 in which said meansfor movably mounting said second operating surface on said bodycomprises a diaphragm, spring means acting on said diaphragm for movingsaid second operating surface in a first direction to its lowerposition, said body having a space defined by wall means and saiddiaphragm, the other of said sections of said second passageway incommunication with said mounting means being connected to said space,said mounting means being acted upon by air at a partial vacuum whensaid valve moves to its open position and said second passageway isopen, such air at a partial vacuum and in said space being operable toovercome said spring means and more said second operating surface in asecond opposite direction to its upper position, and said wall meansdefining said space having an opening for ambient air at atmosphericpressure to flow into said space.

10. A vacuum cleaner nozzle which includes a. first and second operatingsurfaces for performing different types of cleaning,

b. said nozzle comprising a body including means defining a firstpassageway having a suction inlet at the vicinity of said operatingsurfaces and an outlet adapted to be connected to a source of supply ofair at a partial vacuum, said first passageway providing a path of flowfor air between the inlet and outlet,

. means for mounting said second operating surface on said body formovement between upper and lower positions with respect to said firstoperating surface, (1 said first operating surface being operable toclean a soft porous surface with which it is in contact when said secondoperating surface is in its upper position and (2) said second operatingsurface being operable to clean a smooth surface with which it is incontact when it is in its lower position,

. structure defining a space,

. said mounting means being operable (l) to move said second operatingsurface relative to said first operating surface from its lower positionto its upper position responsive to air in said space at a firstpressure which is at a partial vacuum and operable (2) to move saidsecond operating surface relative to said first operating surface to itslower position responsive to air in said space at a second higherpressure,

f. means providing a second passageway for air between said firstpassageway and said space,

g. valve means in said second passageway which is movable between closedand open positions,

h. means operable to control said valve means responsivc solely to thepressure differential of air in first and second regions in said firstpassageway which varies with the physical characteristics of the surfacebeing cleaned by the nozzle and over which said body is moved, saidvalve means moving to its closed position when said pressuredifferential is above a definite value and the rate at which air flowsthrough said first passageway is relatively high and in a first rangeand moving to its open position when said pressure differential is belowthe definite value and the rate at which air flows through said firstpassageway is relatively low and in a second lower range, andi. saidstructure defining said space being so constructed and formed that,during normal operation of said nozzle when said outlet is connected toa source of supply of air at a partial vacuum, the air in said spacewill be at the first pressure when said valve means is open and at thesecond higher pressure when said valve means is closed.

11. A vacuum cleaner nozzleas set forth in claim in which said means formounting said second operating surface on said body for movement betweenits upper and lower positions comprises a flexible diaphragm.

12. A vacuum cleaner nozzle as set forth in claim 11 i in which saidstructure defining said space includes said flexible diaphragm.

113.A vacuum cleaner nozzle as set forth in claim 12 which includesresilient means biasing said flexible diaphragm to render the latteroperable to move said second operating surface in one direction to itslower position when said valve means is closed and the air in said spaceis at the second higher pressure, the air in said space at the firstpressure, which is at a partial vacuum when said valve means is open,overcoming the biasing action of said flexible diaphragm means by saidresilient means to move said second operating surface in the oppositedirection to its upper position.

14. A vacuum cleaner nozzle as set forth in claim 10 in which saidstructure defining said space is so constructed and formed that, duringnormal operation of said nozzle when said outlet is connected to asource of supply of air at a partial vacuum, ambient air can flow intosaid space and the air therein will be at the second higher pressurewhich is at or approaches atmospheric pressure when said valve means isclosed and at the first pressure which is at a partial vacuum when saidvalve means is open.

15. A vacuum cleaner nozzle as set forth in claim 14 in which saidstructure defining said space includes a wall member having an openingfor ambient air to flow into said space.

16. A vacuum cleaner nozzle which includes a. first and second operatingsurfaces for performing different types of cleaning,

b. said nozzle comprising a body including means defining a firstpassageway having a suction inlet at the vicinity of said operatingsurfaces and an outlet adapted to be connected to a source of supply ofair at a partial vacuum, said first passageway providing a path of flowfor air between the inlet and outlet,

. means for mounting said second operating surface on said body formovement between upper and lower positions with respect to said firstoperating surface, (I said first operating surface being operable toclean a soft porous surface with which it is in contact when said secondoperating surface is in its upper position and (2) said second operatingsurface being operable to clean a smooth surface with which it is incontact when it is in its lower position,

d. structure defining a space,

e. said mounting means being operable (l) to move said second operatingsurface relative to said first operating surface from its lower positionto its upper position responsive to air in said space at a firstpressure which is at a partial vacuum and operable (2) to move saidsecond operating surface relative to said first operating surface to itslower position responsive to air in said space at a second higherpressure,

f. means providing a second passageway for air between a first region insaid first passageway and said space,

g. valve means in said second passageway which is movable between closedand open positions,

h. means providing a third passageway for air which extends from asecond region in said first passageway to said valve means, said thirdpassageway being out of communication with said second passageway,

i. said valve means and second and third passageways being soconstructed and arranged that said valve means moves to its closedposition when the pressure differential of air in said first and secondregions of said first passageway is above a definite value and the rateat which air flows through said first passageway is in a first range andmoves to its open position when the pressure differential of air in saidfirst and second regions of said first passageway is below the definitevalue and the rate at which air flows through said first passageway isin a second lower range, and

j. said structure defining said space being so constructed and formedthat, during normal operation of said nozzle when said outlet isconnected to a source of supply air at a partial vacuum, the air in saidspace will be at the first pressure when said valve means is open and atthe second higher pressure when said valve means is closed.

17. A vacuum cleaner nozzle as set forth in claim 16 in which said firstand second regions in said first passageway are spaced apart lengthwisethereof.

18. A vacuum cleaner nozzle as set forth in claim 17 in which said meansdefining said first passageway is of reduced crosssectional area at azone between said first and second regions.

19. A vacuum cleaner nozzle as set forth in claim 16 in which said valvemeans comprises a diaphragm, said third passageway being out ofcommunication with said second passageway by said diaphragm.

20. A vacuum cleaner nozzle as set forth in claim 19 in which said thirdpassageway extending from said second region in said first passagewayterminates at said diaphragm.

21. A vacuum cleaner nozzle as set forth in claim 20 in which saidsecond passageway includes first and second sections, said first sectionat one end being in communication which said first region in said firstpassageway and at the other end terminating at an opening defining aseat against which said diaphragm bears when said valve means is closed,said second section at one end being in communication with said spaceand at the other end terminating at an opening of annular form which isadjacent to said diaphragm and disposed about said seat.

22. A vacuum cleaner nozzle as set forth in claim 21 in which the areaof said diaphragm includes one portion substantially equal to thecross-sectional area of said seat and another portion substantiallyequal to the cross-sectional area of the opening of annular form at theother end of said second section of said second passageway.

23. A vacuum cleaner nozzle as set forth in claim 21 in which saiddiaphragm has a larger cross-sectional area than the cross-sectionalarea of said seat with the radial distance of said diaphragm from saidseat to its periphery being such that zones of said diaphragm at bothides of the edge of said seat and immediately adjacent thereto flex andmove in substantially the same manner.

24. A vacuum cleaner nozzle as set forth in cliam 23 in which said seathas a sharp edge.

25. A vacuum cleaner nozzle as set forth in claim 21 in which said firstsection of said second passageway, at a zone adjacent to said seat, isof larger crosssectional area than the portion thereof nearer to saidfirst passageway.

26. A vacuum cleaner nozzle as set forth in cliam 25 in which the airoutlet end of said zone is of reduced cross-sectional area and throttlesair in its path of flow from said diaphragm to said first passageway insaid first section of said second passageway.

1. A vacuum cleaner nozzle which includes a. first and second operatingsurfaces for performing different types of cleaning, b. said nozzlecomprising a body including means defining a first passageway having asuction inlet at the vicinity of said operating surfaces and an outletadapted to be connected to a source of supply of air at a partialvacuum, said first passageway providing a path of flow for air betweenthe inlet and outlet, c. means for mounting said second operatingsurface on said body for movement between upper and lower positions withrespect to said first operating surface, said first operating surfacefunctioning to clean an object with which it is in contact when saidsecond operating surface is in its upper position and said secondoperating surface functioning to clean an object with which it is incontact when it is in its lower position, d. means providing a secondpassageway having one end thereof in communication with a first regionof said first passageway and the opposite end thereof in communicationwith said movable mounting means, e. a valve which is movable betweenopen and closed positions and in said second passageway intermediate theends thereof and acted upon by the pressure differential of air at apartial vacuum in said first region of said first passageway and of airAt a partial vacuum in a second region of said first passageway, f. saidvalve moving to its closed position when said pressure differential isabove a definite value and the rate at which air flows through saidfirst passageway is in a first range and moving to its open positionwhen said pressure differential is below the definite value and the rateat which air flows through said first passageway is in a second lowerrange, and g. said movable mounting means being rendered operable tomove said second operating surface to its upper position when said valveis in its open position.
 2. A vacuum cleaner nozzle as set forth inclaim 1 in which said second region in said first passageway is removedlengthwise therein from said first region, and means between said firstand second regions for throttling air flowing in said first passagewaybetween said regions.
 3. A vacuum cleaner nozzle as set forth in claim 2in which said second passageway has a break at which the adjacent endsof two sections thereof terminate, one of said sections in communicationwith said first region of said first passageway terminating in anopening at said break which defines a seat against which one face ofsaid valve is adapted to move in sealing relation therewith, a firstsegment of said one face of said valve moving against said seat defininga first part of the area of said valve, and the other of said sectionsof said second passageway in communication with said movable mountingmeans also terminating at an opening at said break, a second segment ofsaid one face of said valve co-acting with the last-mentioned opening ofthe other of said sections defining a second remaining part of saidvalve area, and the opposite face of said valve being in communicationwith said second region of said first passageway.
 4. A vacuum cleanernozzle as set forth in claim 3 in which said valve comprises a flexiblediaphragm, and means for securing the peripheral edge portion of saiddiaphragm in said body adjacent to said break in said second passageway,the ratio of the area of the first part of said diaphragm to the entirecross-sectional area thereof being such that flexing of said first andsecond segments of said diaphragm at opposing sides of said seat insubstantially the same manner is promoted when said diaphragm moves toits closed position.
 5. A vacuum cleaner nozzle as set forth in claim 3in which said valve comprises a resilient diaphragm, means for securingthe peripheral edge portion of said diaphragm in said body adjacent tosaid break in said second passageway, said seat being defined by a sharpedge formed at said break by the opening in said first section of saidsecond passageway, and said diaphragm having a larger cross-sectionalarea than the cross-sectional area of said seat with the radial distanceof said diaphragm from said seat to the peripheral edge portion thereofbeing such that zones of said diaphragm at both sides of the edge ofsaid seat and immediately adjacent thereto flex and move insubstantially the same manner.
 6. A vacuum cleaner nozzle as set forthin claim 1 in which said means for movably mounting said secondoperating surface on said body comprises a diaphragm, spring meansacting on said diaphragm for moving said second operating surface in afirst direction to its lower position, and said movable mounting meansbeing acted upon by air at a partial vacuum when said valve moves to itsopen position and said second passageway is open, such air at a partialvacuum being operable to overcome said spring means and move said secondoperating surface in a second opposite direction to its upper position.7. A vacuum cleaner nozzle as set forth in claim 3 in which said firstsection of said second passageway includes two portions, a first portionof which is nearer to said first region of said first passageway and asecond portion of which is nearer to said valve and has the openingdefining said seat, and the cross-sectional area of said second poRtionat said seat being greater than the cross-sectional area of said firstportion.
 8. A vacuum cleaner nozzle as set forth in claim 7 in which thejunction between the first and second portions has a restriction whichthrottles air flowing therethrough when said valve is in its openposition.
 9. A vacuum cleaner nozzle as set forth in claim 3 in whichsaid means for movably mounting said second operating surface on saidbody comprises a diaphragm, spring means acting on said diaphragm formoving said second operating surface in a first direction to its lowerposition, said body having a space defined by wall means and saiddiaphragm, the other of said sections of said second passageway incommunication with said mounting means being connected to said space,said mounting means being acted upon by air at a partial vacuum whensaid valve moves to its open position and said second passageway isopen, such air at a partial vacuum and in said space being operable toovercome said spring means and more said second operating surface in asecond opposite direction to its upper position, and said wall meansdefining said space having an opening for ambient air at atmosphericpressure to flow into said space.
 10. A vacuum cleaner nozzle whichincludes a. first and second operating surfaces for performing differenttypes of cleaning, b. said nozzle comprising a body including meansdefining a first passageway having a suction inlet at the vicinity ofsaid operating surfaces and an outlet adapted to be connected to asource of supply of air at a partial vacuum, said first passagewayproviding a path of flow for air between the inlet and outlet, c. meansfor mounting said second operating surface on said body for movementbetween upper and lower positions with respect to said first operatingsurface, (1) said first operating surface being operable to clean a softporous surface with which it is in contact when said second operatingsurface is in its upper position and (2) said second operating surfacebeing operable to clean a smooth surface with which it is in contactwhen it is in its lower position, d. structure defining a space, e. saidmounting means being operable (1) to move said second operating surfacerelative to said first operating surface from its lower position to itsupper position responsive to air in said space at a first pressure whichis at a partial vacuum and operable (2) to move said second operatingsurface relative to said first operating surface to its lower positionresponsive to air in said space at a second higher pressure, f. meansproviding a second passageway for air between said first passageway andsaid space, g. valve means in said second passageway which is movablebetween closed and open positions, h. means operable to control saidvalve means responsive solely to the pressure differential of air infirst and second regions in said first passageway which varies with thephysical characteristics of the surface being cleaned by the nozzle andover which said body is moved, said valve means moving to its closedposition when said pressure differential is above a definite value andthe rate at which air flows through said first passageway is relativelyhigh and in a first range and moving to its open position when saidpressure differential is below the definite value and the rate at whichair flows through said first passageway is relatively low and in asecond lower range, and i. said structure defining said space being soconstructed and formed that, during normal operation of said nozzle whensaid outlet is connected to a source of supply of air at a partialvacuum, the air in said space will be at the first pressure when saidvalve means is open and at the second higher pressure when said valvemeans is closed.
 11. A vacuum cleaner nozzle as set forth in claim 10 inwhich said means for mounting said second operating surface on said bodyfor movement between its upper and lowEr positions comprises a flexiblediaphragm.
 12. A vacuum cleaner nozzle as set forth in claim 11 in whichsaid structure defining said space includes said flexible diaphragm. 13.A vacuum cleaner nozzle as set forth in claim 12 which includesresilient means biasing said flexible diaphragm to render the latteroperable to move said second operating surface in one direction to itslower position when said valve means is closed and the air in said spaceis at the second higher pressure, the air in said space at the firstpressure, which is at a partial vacuum when said valve means is open,overcoming the biasing action of said flexible diaphragm means by saidresilient means to move said second operating surface in the oppositedirection to its upper position.
 14. A vacuum cleaner nozzle as setforth in claim 10 in which said structure defining said space is soconstructed and formed that, during normal operation of said nozzle whensaid outlet is connected to a source of supply of air at a partialvacuum, ambient air can flow into said space and the air therein will beat the second higher pressure which is at or approaches atmosphericpressure when said valve means is closed and at the first pressure whichis at a partial vacuum when said valve means is open.
 15. A vacuumcleaner nozzle as set forth in claim 14 in which said structure definingsaid space includes a wall member having an opening for ambient air toflow into said space.
 16. A vacuum cleaner nozzle which includes a.first and second operating surfaces for performing different types ofcleaning, b. said nozzle comprising a body including means defining afirst passageway having a suction inlet at the vicinity of saidoperating surfaces and an outlet adapted to be connected to a source ofsupply of air at a partial vacuum, said first passageway providing apath of flow for air between the inlet and outlet, c. means for mountingsaid second operating surface on said body for movement between upperand lower positions with respect to said first operating surface, (1)said first operating surface being operable to clean a soft poroussurface with which it is in contact when said second operating surfaceis in its upper position and (2) said second operating surface beingoperable to clean a smooth surface with which it is in contact when itis in its lower position, d. structure defining a space, e. saidmounting means being operable (1) to move said second operating surfacerelative to said first operating surface from its lower position to itsupper position responsive to air in said space at a first pressure whichis at a partial vacuum and operable (2) to move said second operatingsurface relative to said first operating surface to its lower positionresponsive to air in said space at a second higher pressure, f. meansproviding a second passageway for air between a first region in saidfirst passageway and said space, g. valve means in said secondpassageway which is movable between closed and open positions, h. meansproviding a third passageway for air which extends from a second regionin said first passageway to said valve means, said third passagewaybeing out of communication with said second passageway, i. said valvemeans and second and third passageways being so constructed and arrangedthat said valve means moves to its closed position when the pressuredifferential of air in said first and second regions of said firstpassageway is above a definite value and the rate at which air flowsthrough said first passageway is in a first range and moves to its openposition when the pressure differential of air in said first and secondregions of said first passageway is below the definite value and therate at which air flows through said first passageway is in a secondlower range, and j. said structure defining said space being soconstructed and formed that, during normal operation of said nozzle whensaid outlet is connected to a source of supply air at a partial vacuum,the air in said space will be at the first pressure when said valvemeans is open and at the second higher pressure when said valve means isclosed.
 17. A vacuum cleaner nozzle as set forth in claim 16 in whichsaid first and second regions in said first passageway are spaced apartlengthwise thereof.
 18. A vacuum cleaner nozzle as set forth in claim 17in which said means defining said first passageway is of reducedcross-sectional area at a zone between said first and second regions.19. A vacuum cleaner nozzle as set forth in claim 16 in which said valvemeans comprises a diaphragm, said third passageway being out ofcommunication with said second passageway by said diaphragm.
 20. Avacuum cleaner nozzle as set forth in claim 19 in which said thirdpassageway extending from said second region in said first passagewayterminates at said diaphragm.
 21. A vacuum cleaner nozzle as set forthin claim 20 in which said second passageway includes first and secondsections, said first section at one end being in communication with saidfirst region in said first passageway and at the other end terminatingat an opening defining a seat against which said diaphragm bears whensaid valve means is closed, said second section at one end being incommunication with said space and at the other end terminating at anopening of annular form which is adjacent to said diaphragm and disposedabout said seat.
 22. A vacuum cleaner nozzle as set forth in claim 21 inwhich the area of said diaphragm includes one portion substantiallyequal to the cross-sectional area of said seat and another portionsubstantially equal to the cross-sectional area of the opening ofannular form at the other end of said second section of said secondpassageway.
 23. A vacuum cleaner nozzle as set forth in claim 21 inwhich said diaphragm has a larger cross-sectional area than thecross-sectional area of said seat with the radial distance of saiddiaphragm from said seat to its periphery being such that zones of saiddiaphragm at both sides of the edge of said seat and immediatelyadjacent thereto flex and move in substantially the same manner.
 24. Avacuum cleaner nozzle as set forth in claim 23 in which said seat has asharp edge.
 25. A vacuum cleaner nozzle as set forth in claim 21 inwhich said first section of said second passageway, at a zone adjacentto said seat, is of larger cross-sectional area than the portion thereofnearer to said first passageway.
 26. A vacuum cleaner nozzle as setforth in claim 25 in which the air outlet end of said zone is of reducedcross-sectional area and throttles air in its path of flow from saiddiaphragm to said first passageway in said first section of said secondpassageway.